1. Field of the Invention
The invention relates to an optoelectronic device and method of fabricating the same, e.g., a photo-detector, a solar cell and so on, and more in particular, to an optoelectronic device with high photoelectric conversion efficiency and method of fabricating the same.
2. Description of the Prior Art
Along with the rapid development of photoelectric industry, versatile optoelectronic devices such as light-emitting diodes, laser diodes, photo-detectors, solar cells, etc., have been extensively used in many fields of applications. Moreover, with the progress of relative technologies, user's requirement for performance such as luminescence efficiency or photoelectric conversion efficiency of the photoelectric device is higher and higher.
Generally speaking, formation of a passivation layer on the surface of an optoelectronic device can improve, to some extent, some properties of the optoelectronic device, such as luminescence efficiency or photoelectric conversion efficiency. Taking a silicon solar cell as an example, the silicon solar cell with high photoelectric conversion efficiency conventionally uses a thermal oxide layer as a surface passivation layer. To form the thermal oxide layer, the silicon wafer is exposed to an oxygen ambient at a high temperature such that the surface of the silicon wafer is oxidized to form the passivation layer of silicon dioxide. The passivation layer formed on the surface of the silicon solar cell can provide surface passivation effect so as to improve photoelectric conversion efficiency of the silicon solar cell.
However, the passivation layers formed by traditional techniques generally have some drawbacks such as poor control of film thickness, insufficient surface coverage, high defect density, and so on. Such poor-quality passivation layers cannot benefit a lot in improving the properties of optoelectronic devices.
In addition, the processing temperature at which the oxide layers are formed is often up to several hundred, or even over one thousand degrees Celsius. The high processing temperature could destroy the finished structures of the optoelectronic devices, or cause the malfunction or damage of equipments, so as to lower the reliability of process and the availability of equipments.
Accordingly, a scope of the invention is to provide an optoelectronic device and method of fabricating the same to solve aforesaid problems.